'idl_module': only the 'name' property is allowed here
idl_module usage directly on a function declaration cannot have any parameters other than name.
The following sample generates C3371:
[idl_module(name="Name", dllname="Some.dll")]; [idl_module(name="Name", helpstring="Some help")] // C3371 int f1(); // try // [idl_module(name="Name")] // int f1(); void main(){ }